Method of producing heating and illuminating gas



Feb l, Q. A F. KUNBERGER QZYZ METHOD OF PRODUCING HEATING AND ILLUMINATING GAS Filed June 13 1925 I l z I l I l 1 I l l u l I l I l l I x l l l l Q @Y @um m( ATTORNEY.

Patented Feb. 10, 1931 UNITED STATES PATENT OFFEC,

ALBERT F. KUNBERGER, OF SWARTHMORE, PENNSYLVANIA, ASSIGNOR TO THE UNITED GAS IMPROVEMENT COMPANY, OF PHILADELPHIA, PENNSYLVANIA, .A1-CORPORA- TION OF PENNSYLVANIA METHOD F PRODUCING HEATING AND ILLUMINATING GAS Application led June 13,

In the processes or'methods heretofore einployed in the manufacture of commercial heating or illuminating gases by total gasiication of coal the difficulty has been that the gases'which have been yielded or produccdwere deficient in heating Values, such values being less than 400 B. t. u. per cubic foot of gas. One practice heretofore followed in order to increase the heating Value o of the gases so as to bring them upto the 5 ment 'of which gases possessing the requisite heating or illuminating values may be produced bythe total gasification of coal without the introduction into the said gases of an oil vapor or other enriching vapor. t

It is also an object of my invention to provide a method whereby the necessary reactions may be brought about in the generating chamber to produce a gas comprisin'g the necessary ingredients or elements in the proportions necessary to produce a commercial fuel or illuminating gas having the requisite heating vaille, thereby rendering it unnecessary to enrich the same by the introduction thereinto of an oil or other en- 40 riching vapor or gas.

Another object of the invention is to provide a method wherein a metal catalyst, which may be discarded with the ash from the coal in the generator, may be employed to facilitate the reactionsI within the generator whereby a commercial fuel or illuminating gas may be produced having the requisite heating value, which usually is in excess of 500 B. t. u. per cubic foot of gas. I prefer to use iron as the metal catalyst because of 1925. Serial No. 36,800.

its cheapness, but any other suitable metal ma be used.

nother object of the-invention is to provide a process or method including novel steps by the employment of which great economy in the manufacture of heating and illuminating gas is effected.

Although in the carrying out of my invention no particular form or construction of apparatus is necessary some form of apparatus must be used hence, in order to facilitate the description and understanding of the invention, I have illustrated diagrammatically' a form of apparatus which may be employed.

I 'shall first describe briefly the essential parts of the apparatus which I have chosen to illustrate and the manner in which the same is operated and will then describe more in detail the process or method embodying my invention.

In the drawing the parts of the apparatus are shown in vertical section.

Referring to the drawing: 1 designates a generator provided with a grate 2 on which vthe coal within the generator l is supported.

The generator is provided at its upperl end with an opening 3 which is closed by means of a plug or door 4 of any suitable construction. For the purpose of discharging a draft or blast of air through the generator for the purpose of raising the coal or coke therein to a high heat I have provided an air supply pipe 6 which is adapted to be controlled by a valve indicated at 7. The blast gases are conducted through a pipe 8. Passage of the said gases therethrough is adapted to be' controlled by a valve 9. The pipe 8 leads into a receptable or container 10 which contains refractory material mixed orV covered with iron, or iron particles in some form or other, such as borings, scrap, or the like. It may be stated that a small quantity of the metal catalyzer, iron preferred, is mixed in with the coal or coke inthe generator 1 and that as additional coal is introduced into the generator, as will be hereinafter described, an additional quantity of the catalyzer is also introduced 1n order to replenish the same. Replenishment is necessary because of the susk fact that the catalyzer is discharged or discarded with the ash which passes or falls through the grate 2 as the fuel is consumed.l

Because of the discarding -of the catalyzei` with the ash it is necessary from a practical or commercial standpoint that a cheap metal be employed. The passage of the air blast gases, through the receptacle or container 10 4 raises the contents thereof to a red heat, the temperature of which may range from twelve hundred to twenty-five hundred degrees Fahrenheit. The temperatures employed generally range from fifteenhundred to eighteen hundred degrees Fahrenheit. These gases pass from the chamber 10 through a pipe 15, controlled by a valveindicated at 16, into the lower part of a steam boiler 17 of any known construction. The passage of the hot gases through the said boiler heats the water therein to produce steam. The steam thus produced is adapted to be conveyed through a pipe 20 controlled by a valve indicated at 21 into the pipe 15 between the valve 16 thereof and the recep-v tacle or container 10. From the pipe 15 the steam is adapted to flow through the chamber of the receptacle or container 10, where it is partially superheated and partially decomposed into hydrogen and oxygen. The oxygen combines with the iron to form oxid of iron while the hydrogen and undecomposed portions of the steam flow on through a pipe 22 (which may or may not be provided with a valve as desired) which discharges into the f lower end portion of a pipe 23 which is in communication with a hopper 24 which is adapted to be supplied with powdered or pulverized coal containing some iron or iron oxide in a finely divided state. The pipe 23 is provided with a valve indicated at 25 to control the discharge of the rpowdered or pulverized coal from the hopper 24 into the generator 1 and also to prevent the gases from flowing or leaking out through the pipe 23 into the hopper 24.

The coal in powdered or pulverized form may be introduced from the hopper 24 into the generator 1 or it may be introduced in the form of lumps of greater or less bulk or size through the opening 3 .previously referred to. In either case a sufiicient quantity of the, metal catalyzer should be introduced with the coal to take the place of the catalyzer, preferably iron or iron oxide, which shall have been discharged with the ash from `the generator through the grate 2. Vhether the coal be introduced in one way or another into the generator 1 the hydrogen due to its highly heated condition, to the high pressure maintained within the chamber of the generator 1, and to the presence of the catalyst, reacts with the said coal and any coke which may be present to eil'ect gasification thereof to produce a gas having the characteristics desired. The temperature within the generator 1 during the reaction period ma range from nine hundred tol fteen hun red degrees Fahrenheit, but temperatures ranging from twelve hundred to fifteen hundred degrees Fahrenheit are preferred. The steam which is introduced into the generator is decomposed, the hydrogen combining with the carbon of the mass of coke and coal and the oxygen combining with carbon to produce carbon monoxide.

The gas is formed, as -will be hereinafter described, in the generator 1 and when its formation has been completed it is conveyed therefrom through a pipe 30 to a holder or container (not shown) from which it may be supplied for use. The saidpipe 30 is controlled by a valve indicated at 31. I have also provided a pipe 32 controlled by a valve indicated at 33 which `is adapted to be opened automatically in case the pressure within the generator 1 should exceed a predetermined limit. The said pipe 32 constitutes a by-pass from the generator around the valve 31.

When the steam is permitted or allowed to flow from the boiler 17 through the pipe 20 and thence through the container or receptacle 10 into the generator 1 the valves at 7, 9, 16, 25 and 31 are closed. Such closure is necessary in order that the desired pressure within the generator 1 may be obtained. This pressure depends upon the steam pressure of the boiler 17 and may be regulated and controlled by controlling the pressure in the boiler.

The above described operation .having been completed it is repeated, and air blast gases vagain iow from the generator 1 through the chamber 10. These air blast gases include carbon monoxide, which reacts with the iron oxide in the said chamber 10 (produced by the reaction of the steam with the iron present thereinas above described) to reduce the said oxide and produce iron and carbon dioxide. 'I'he latter intermingles with the said air blast gases and flows therewith to the steam boiler 17.

Having now described the apparatus and in a brief way the operation of the same I shall now describe the method embodying my invention by reference to the said apparatus which is illustrative, as previously stated, of one form of apparatus which may be employed in the carrying out or practicing of the' invention.

During the period of combustion or air blasting in the generator 1 the valves at 7, 9 and 16 are open to permit the discharge of a draft of air from pipe 6 into and through the bed of coal in the generator and to permit the passage of the hot gases generated in said generator through the container 10 as described already. The valves at 21, 25 and 31 are closed at this time. The period of combustion having been continued until the required temperature of the refractory material in the-container 10 shall have been attained and until the required amount of steam at the required pressure shall have been pro duced in the boiler 17, after which the valves at 7, 9 and 16 are closed. T he temperature of the refractory material in the container 1() may range from twelve hundred up to twenty-five hundred degrees Fahrenheit. The operations usually are carried out with the temperature of the refractory material in said container ranging from fifteen hundred to eighteen hundred degrees Fahrenheit. After the closing of the valves 7 9' and 16 as stated the valve at 21 is opened. The valve at 25may or maynot be opened. lf it be desired that powdered or pulverized coal mixed with the metal catalyst, such as iron or iron oxide in divided state be introduced simultaneously with the introduction of hydrogen gas and steam from the pipe 22, the waive 25 should be ope at the beginning of said operation to permit a sui'icient quantity of powdered ceal to enter the generator. The said `alve 25 is then closed. The said coal being in powdered or pulverized form is, upon introduction into the generator. 1, instantaneously gasiiied. Instead of introducing powdered coal as described the required amount of coal may be introduced in lump form through the opening at 3.

It has already been stated that the refractory material within the receptacle or con tainer 10 has been raised to a red heat. Upon the opening of the valve 21 and the closing of otherv valves as stated, steam from the boiler 17 flows through the receptacle or container 10 and upon coming into contact `with the refractory material therein is superheated and by reason of the presence of the metallic iron and the influence of high pressure is partly decomposed to form or liberate hydrogen and oxygen. with the metallic iron present to form oxid of iron. The hydrogen whichA is free mixes with the undecomposed superheated steam and the mixture iows from the container 10 through the pipe 22 into the generator 1. These gases, steam and hydrogen, are forced into the mass of coke or coal but usually a mixture. thereof under pressure from the boiler 17. The superheated steam, hydrogen and such other gases as may be present or formed in the generator, are retained under a high pressure as heretofore stated for a period of time during which, due-to the pressure and to the presence of the catalyzer,

preferably iron, therein reactions take place whereby a fuel or illuminating gas possessing the requisite heating values is produced. The pressure within the generator 1 may range from thirty to three hundred pounds per square inch. The operating pressure within the generator l, that is the pressure during the period of reaction between the hydrogen and the steam and the carbon will The latter combines i 'range usually from around one hundred and does not possess as high a heating value as generally is desired. The heating value of a gas produced at such a pressure ranges around 400 B. t. u. per cubic foot of gas and at times slightly below that value. When however the process is carried out at higher pressures and at high. temperatures as described a gas is produced possessing the requisitethermal value. The union of the hydrogen with carbon to form or produce hy.- drocarbon gases, among them methane, is increased in the proportion in which the pressure within the generating chamber is increased. lt will be apparent, therefore, that the pressure factor is one of great importance in the process.

Some of the gases produced by the reactions within the generator 1, which reactions, as before stated, are brought about by the,l sustained high pressure therein and by the presence of the metal catalyzer, are methane, ethane, ethylene, acetylene and some carbon monoxide.

Analyses of gases produced by the proeess above described embodying my invention at pressures averaging thirty pounds per square inch and at high temperatures in the presence of a catalyst as described show an average composition by volume substantially as follows: 2% of carbon dioxide, 13% of carbon monoxide, 10% of methane, 72% Yof hydrogen, 21% of nitrogen and 1% of oxygen. Analyses of gases produced at pressures averaging one hundred and fifty pounds per square inch within the generator at high temperatures and in the presence of a catalyst as described show an average composition by volume substantially as follows: 1% of carbon dioxide, 9% of carbon. monoxide, 32% of methane, 55% of hydrogen, 2% of nitrogen and 1% of hydrocarbon gases other than methane.

The reactions having been completed within the generating chamber the Valve indicated at 31 is opened so that the said gases may flow from the -said chamber into the holder provided therefor. i

It perhaps should be pointed out that during the passage of the steam (H2O) through the receptacle or container 10 reactions take place between the iron and the steam to form ferrie oxide and hydrogen. As already stated, a portion of the steam goes forward as superheated steam.

Assuming now that the reactions have taken place as above described and that the gases have been released from the generator chamber 1 and conducted into aholder, the valve 31 is closed, also the valve 21, while the valves 7, 9 and 16 are reopenedand a blast of air forced through the generator 1 and thence through the receptacle or container 10 and through the flues of the boiler 17. The blast gases thus produced include carbon dioxide, carbon monoxide, and nitrogen, the said gases heilig heated, of course. The carbon monoxide present reacts with the ferric oxide previously produced, as above stated, to reduce the vsame and form metallic iron and carbon dioxide. The latter together with the gases previously mentioned flows forward through the iues of the boiler 17, as previously described.

The method as above described is desirable because of its economy of operation, due to the fact that the combustion of coal or coke in the generator 1 provides the heat for heating the refractory material in the container 10 and for heating the boiler 17 to produce the steam requisite for use in the method. However, the reactions in the chamber of the generator 1 to produce the gas as hereinbefore described are not dependent upon such preheating or combustion of the coal or coke in the generator. It is essential or necessary only that the gases be introduced into thls chamber (from the chamber of the containe` 10 or other source) at high temperatures and retained therein forthe requisite period of time under high pressure and temperature in the presence of coke or coal or a mixture thereof and a suitable metal catalyst, preferably iron.

It will be obvious fromawhat has been said hereinbefore that if steam alone be introduced into the generator, under the conditions of high pressure and high heat and the presence of a catalyst it will be decomposed and that the hydrogen thus freed will react with the carbon of the`coal or coke or a mixture thereof to produce gases, principally methane, and that the oxygen will unite with carbon to produce carbon monoxide.

The term high pressure Wherever employed herein with respect to the pressure within the generator l is intended to signify a pressure ranging from around thirty to three hundred pounds per square inch; and the term high temperature employed with respect to the reaction zone of the chamber of the generator 1 is intended to signify temperatures ranging from nine hundred to fifteen hundred degrees Fahrenheit; and when the term high temperature is employed herein with respect to the refractory material in the container 10 a temperature of not less than twelve hundred degrees Fahrenheit is intended to be signified.

It will be seen that by my invention I have provided a process or method by the 1. The method of producing heating and illuminating gas, which comprises the heating of a mass of coal Within a. chamber to incandescence, said coal having iron or iron oxide in finely divided form mixed therewith, introducing a mixture of hydrogen and super-heated steam into the said mass, simultaneously introducing additional coal into the said chamber, said coal having a small amount of finely divided iron oxide mixed therewith, and subjecting the gases within the said chamber for a period of time to steam pressure Which may range from 30 pounds to 300 pounds per square inch to cause the hydrogen to combine with the carbon to form hydrocarbon gases.

2. The method of producing heating and illuminating gas of a heating value not less than 400 B. t. u. per cubic foot, which comprises the heating of a mixture of coal and finely divided iron to incandesccnce within a generator, heating a mixture of refractory material and iron within a separate chamber to red heat, passing steam from a boiler through said last mentioned chamber Wherein a portion of the steam is decomposed to produce hydrogen and the remainder of the steam superheated, introducing the mixture of hydrogen and superheated steam into the said generator containing the mixture of finely divided iron and coal heated to incandescence. and subjecting the gases within the said generator to high pressure, causing hydrogen to combine with carbon to produce the said gas.

3. The method of producing heating and illuminating gas, said gas having a heating value of not less than 400 B. t. u. per cubic foot, which comprises the heating of a mixture of coal and finely divided iron or iron oxide to incandescence within a generator, heating a mixture of refractory material and iron within a chamber by the air blast gases from the said generator, employing the said blast gases for heating the water in a boiler to produce steam at the pressure desired, thereafter passing the said steam through the said mixture of refractory material and iron, a portion of the said steam being decomposed into hydrogen and oxygen While the remainder thereof is superheated. discharging the mixture of hydrogen and superheated steam into the incandescent mass within the said generator, simultaneously introducing a mixture of powdered coal and finely divided iron or iron oxide along with the mixture of hydrogen and superheated steam into the said incandescent mass, and

employing the steam from the said boiler to maintain a high pressure Within the said generator which cooperates with the high temperature therein to produce the said gas.

4. The method of producing heating and illuminating gas having a heating value which may range from not less than 400 B. t. u. t0 more than 500 B. t. u. per cubic foot, which comprises the heating of a mixture of coal and a finely ,divided catalyst to incandescence Within a generator, thereafter introducing into the mass within s aid generator a mixture of hydrogen and superheated steam, subjecting the gases Within said chamber to high pressure and temperature to cause the hydrogen to unit with the coal to produce said gas, the latter including methane, acetylene, ethylene, ethane and carbon monoxide.

5. The method of producing heating and illuminating gas having a heating value which may range from not less than 400 B. t. u. to above 500 B. t. u. per cubic foot, which comprises the heating of a mass of coal to incandescence in the chamber of a generator, passing the hot gases from said generator durin the said heating operationv through a cham er containing a body of refractory material with which is mixed iron,

thereafter generating steam by` the transfer of heat from the said gases to Water contained in a boiler, conveying the steam thus produced through the said refractory material wherein 'hydrogen and oxygen are produced b decomposition of steam, and conveying t e hydrogen into the chamber of the said generator and maintaining the same therein under high. pressure to cause union of the hydrogen with thevcarbon of said coal to produce the said as.

6. The methoil of pro ucing heating and illuminating gas having a heating value of not less than 400 B. t. u. per cubic foot, which comprises heating a mass of4 coal to incandescence within the chamber of a generator conductin the hot blast gases from hamber durlng such operation through a chamber containing a body of refractory material with which is mixed finely divided iron or iron oxide or a mixture thereof, generating steam by the transfer of heat from said gases to water contained in a boiler, conveying the steam thus produced from said boiler through the chamber containing the said refractory material wherein a portion Iof the steam is decomposed to produce hydro en and oxygen, the remainder of the steam being superheated, conveying the said hydrogen and superheated steam into the chamber of said generator and into contact with the mass of lncandescent coal ther'ein, the said steam being decomposed therein into hydrogen and oxygen, and maintain-l ing the gases in said generator chamber under lugh pressure to cause union of the hy- 

